Ephesians 1:13-14. “In Whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in Whom also after that ye believed, ye were sealed with the Holy Spirit of promise, Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of His glory.”
These verses take us back to verse 12, where Paul says that we shoul be to the praise of His glory, who first trusted in Christ. First, the Jews received the gospel, and then the Gentiles also began to trust in Christ. Many who heard the gospel for the first time understood and believed; others came to faith more slowly, But one thing was certain: The moment a soul turned to Christ in repentance and faith, trusting Him only for salvation, that soul was sealed with the promise of the Holy Spirit. Upon salvation, the Holy Spirit indwells a new believer, and seals that person for all eternity. Two other places in the New Testament that teach this same principle are 2 Cor. 1:22 and Ephesians 4:30.
A seal was a stamp of ownership, a mark of approval. In Paul’s day, it was a drop of hot wax that was stamped, as it cooled, with the unique mark of, for instance, the letter-writer. Once it was cooled and the letter was sealed, it was actually illegal for anyone but the recipient to open it.
Both Corinth and Ephesus were great centers of the lumber industry in ancient times. A raft of logs would be brought from the Black sea and notice sent to the different lumber firms that the raft was in the harbor. The lumber firms sent their men out, and as they examined the rafts of logs, they would select what they wanted and pay down a little earnest money. At that point, a wedge was cut into each log that was chosen by a company. This wedge was called the seal. The logs may be left there in the harbor for many weeks, but each was sealed by the company that purchased it.
The sealing of the Holy Spirit is the earnest of our inheritance with Jesus Christ, Who has redeemed us. We will be drawn out on the day of redemption, because we are His.